Barium fluoride

Colorless to white crystalline solid

Fixed

4.83 g · cm -3 ( 20 ° C)

1355 ° C

2260 ° C

Slightly soluble in water: 1.2 g · l -1 ( 25 ° C)

1.4744

Risk

1 mg · m-3

-1207.1 KJ / mol

Template: Infobox chemical / molecular formula search available

Barium is a chemical compound of barium and one of the fluorides. It is a colorless crystalline solid.

Occurrence

In nature, barium occurs in the form of the rare mineral Frankdicksonit.

Production and representation

If its solubility product is exceeded, barium precipitates upon concentration barium and fluoride-containing aqueous solutions.

Properties

Such as calcium and strontium fluoride, barium fluoride crystallize in the cubic fluorite structure. In addition to the stable at normal conditions structure, two high-pressure modifications are known in them the barium is coordinated nine - or eleven-fold.

Above 3 GPa pressure, the orthorhombic lead (II ) chloride structure in which crystallize the other Bariumhalogenide forms. Another phase transition occurs at 12 GPa. Above this pressure, the hexagonal structure Ni2In the most stable.

In the gas phase are barium fluoride molecules, contrary to the predictions of the VSEPR model is not linear but bent with an angle of 126 °. Responsible for this are relativistic effects.

Use

Barium fluoride single crystals are optically transparent over a wide range of 150 nm in the ultraviolet to 15 microns in the infrared. This can be used for optical devices. Like other barium fluorides is a flux in the production of light metals, alloys, and in the email industry.

Is barium fluoride doped with lanthanide, it can be used as a material for fiber laser.